Turns out this is something directly in klibc in the case of xenial: since xenial is not yet using isc-dhcp for IPv4 DHCP, since that was deemed too intrusive a change for xenial.
In other words, while DHCPv6 is done via isc-dhcp, DHCPv4 is done via ipconfig (klibc); which will need to be fixed to follow the same logic as isc-dhcp w.r.t DOMAINSEARCH handling. In general, I think having DOMAINSEARCH contain the existing DNS domain if it's not otherwise set by the DHCP server is sensible. I set the xenial task to High since it might actually impact a lot of people, but it's not as high for artful/zesty given that isc-dhcp is used instead (still ought to land there since people might want to use ipconfig on their own, etc.). ** Changed in: isc-dhcp (Ubuntu Xenial) Status: Invalid => Triaged -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to isc-dhcp in Ubuntu. https://bugs.launchpad.net/bugs/1713747 Title: missing DOMAINSEARCH in initramfs output files if the DHCP server doesn't provide one Status in isc-dhcp package in Ubuntu: Fix Released Status in klibc package in Ubuntu: Triaged Status in isc-dhcp source package in Xenial: Triaged Status in klibc source package in Xenial: Triaged Status in isc-dhcp source package in Zesty: Fix Committed Status in klibc source package in Zesty: Triaged Bug description: [Impact] Systems booted off the network where the DHCP server provides a domain name but no search domains may wish to rely on the domain name as a search value (as is done in isc-dhcp in userland, outside the initramfs), to be able to use short names for resolving hosts. [Test cases] 1) Boot a system with a remote root over the network - Typically this requires adding ip=(some IP settings) or ip=dhcp on the kernel command-line, and is better done automatically. One good setup for this is to use MaaS to configure the system; where it will require a remote root over iSCSI. 2) Break boot in the initramfs (adding 'break=bottom' or 'break=premount' to stop in the initramfs at its end, or just before it mounts filesystems) 3) Validate the contents of /etc/resolv.conf [Regression potential] Potential regressions would include incorrectly resolving names, bad configuration of /etc/resolv.conf (invalid values for the fields, or missing fields), or even failure to mount the remote root in the cases where name resolution is required to find the remote server. -- For networked systems, for instance booting with an iSCSI root, dhclient writes an output file in the form of /run/net-<iface>.conf that contains data for other programs to consume. This allows, for instance, open-iscsi to get the right information and properly connect to the server to mount the root filesystem. It is common for DHCP servers to only provide a domain name value, and no search domains. In this case, isc-dhcp doesn't currently write DOMAINSEARCH, but people may wish to use short names to resolve things (such as in iSCSI server). In the not-initramfs dhclient-script, when domain_search isn't provided but domain_name is, domain_name is written to the search string. If both are provided, domain_search is written. The initramfs enter hook should do the same. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1713747/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp